When customizing view or playing games, we often use the keyboard to trigger events and screen triggers! Keyboard triggers events in a custom view (e.g. OnKeyDown (int keycode, keyevent event)) and screen triggering events (Ontouchevent (Motionevent event) And how are keyboard triggers (such as: OnKeyDown (int keycode, keyevent event)) and screen triggering events (Ontouchevent (Motionevent event)) interacting with the activity? What is a principle of operation? Let's take a look at the following:
1, screen trigger event: Which activity or view, the control at the top of the first trigger in this control screen triggering event, return value if it is the default or false will be a layer of down to pass! If the return value is true, it will not be passed down after the action is done!
2, the keyboard trigger event: This principle and screen trigger event is similar, but different, when not set control in focus, generally press the keys on the keyboard trigger is the activity in the keyboard trigger events (such as: OnKeyDown int keycode, keyevent Event)).
Here's an example.：
For example, when playing games, we often customize the view, we generally like and use the trigger in this view (Gameview) Trigger events and screen triggering events, but for example: onKeyDown (int keycode, keyevent event)), In general, when we press the keyboard directly triggered by the activity in the keyboard trigger event, how to let it directly trigger (Gameview) in the keyboard trigger events?
The first of these methods：
Example 1:
Copy Code code as follows:
View Code
Package net.loonggg.project;
Import android.app.Activity;
Import Android.os.Bundle;
Import android.view.KeyEvent;
Import android.view.MotionEvent;
public class Mainactivity extends activity {
Private Gameview Gameview;
@Override
public void OnCreate (Bundle savedinstancestate) {
Super.oncreate (savedinstancestate);
Gameview = new Gameview (this);
Setcontentview (Gameview);
}
@Override
public boolean onKeyDown (int keycode, keyevent event) {
System.out.println ("mainactivity:" + "KeyCode:" + keycode + "Evnet:"
+ event);
Return Super.onkeydown (KeyCode, event);
}
@Override
public boolean ontouchevent (Motionevent event) {
System.out.println ("mainactivity:" + "event:" + Event + "x:"
+ event.getx () + "y:" + event.gety ());
Return Super.ontouchevent (event);
}
}
Package net.loonggg.project;
Import Android.content.Context;
Import Android.graphics.Canvas;
Import Android.graphics.Color;
Import Android.graphics.Paint;
Import android.view.KeyEvent;
Import android.view.MotionEvent;
Import Android.view.View;
public class Gameview extends View {
Private Paint Paint;
private int pointx;
private int pointy;
Public Gameview {
Super (context);
Set Gameview to get focus
This.setfocusable (TRUE);
Paint = new paint ();
Paint.setcolor (Color.yellow);
Thread t = new Thread (new Mythread ());
T.start ();
}
@Override
protected void OnDraw (Canvas Canvas) {
Super.ondraw (canvas);
Canvas.drawcircle (Pointx, pointy, paint);
}
Class Mythread implements Runnable {
@Override
public void Run () {
while (true) {
try {
Thread.Sleep (3000);
Pointy = pointy + 10;
Pointx = Pointx + 10;
if (Pointx > 200) {
Break
}
catch (Interruptedexception e) {
E.printstacktrace ();
}
GameView.this.postInvalidate ();
}
}
}
@Override
public boolean onKeyDown (int keycode, keyevent event) {
System.out.println ("Gameview:" + "KeyCode:" + keycode + "Evnet:"
+ event);
This event will not spread out
return true;
}
@Override
public boolean ontouchevent (Motionevent event) {
System.out.println ("Gameview:" + "event:" + Event + "x:"
+ event.getx () + "y:" + event.gety ());
This event will not spread out
return true;
}
}
The second method：
Copy Code code as follows:
View Code
Package net.loonggg.project;
Import android.app.Activity;
Import Android.os.Bundle;
Import android.view.KeyEvent;
Import android.view.MotionEvent;
public class Mainactivity extends activity {
Private Gameview Gameview;
@Override
public void OnCreate (Bundle savedinstancestate) {
Super.oncreate (savedinstancestate);
Gameview = new Gameview (this);
Setcontentview (Gameview);
}
@Override
public boolean onKeyDown (int keycode, keyevent event) {
System.out.println ("mainactivity:" + "KeyCode:" + keycode + "Evnet:"
+ event);
Pass the event to Gameview
Gameview.onkeydown (KeyCode, event);
Return Super.onkeydown (KeyCode, event);
}
@Override
public boolean ontouchevent (Motionevent event) {
System.out.println ("mainactivity:" + "event:" + Event + "x:"
+ event.getx () + "y:" + event.gety ());
Pass the event to Gameview
Gameview.ontouchevent (event);
Return Super.ontouchevent (event);
}
}
Package net.loonggg.project;
Import Android.content.Context;
Import Android.graphics.Canvas;
Import Android.graphics.Color;
Import Android.graphics.Paint;
Import android.view.KeyEvent;
Import android.view.MotionEvent;
Import Android.view.View;
public class Gameview extends View {
Private Paint Paint;
private int pointx;
private int pointy;
Public Gameview {
Super (context);
Paint = new paint ();
Paint.setcolor (Color.yellow);
Thread t = new Thread (new Mythread ());
T.start ();
}
@Override
protected void OnDraw (Canvas Canvas) {
Super.ondraw (canvas);
Canvas.drawcircle (Pointx, pointy, paint);
}
Class Mythread implements Runnable {
@Override
public void Run () {
while (true) {
try {
Thread.Sleep (3000);
Pointy = pointy + 10;
Pointx = Pointx + 10;
if (Pointx > 200) {
Break
}
catch (Interruptedexception e) {
E.printstacktrace ();
}
GameView.this.postInvalidate ();
}
}
}
@Override
public boolean onKeyDown (int keycode, keyevent event) {
System.out.println ("Gameview:" + "KeyCode:" + keycode + "Evnet:"
+ event);
Return Super.onkeydown (KeyCode, event);
}
@Override
public boolean ontouchevent (Motionevent event) {
System.out.println ("Gameview:" + "event:" + Event + "x:"
+ event.getx () + "y:" + event.gety ());
Return Super.ontouchevent (event);
}
}
In this case, the second method is recommended, because the first method has a simulator that cannot be used!
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